1. Field of the Invention
The present invention relates to a new oxime derivative; a photopolymerizable composition which comprises a photopolymerization initiator having a specific structure and is preferably used in UV ink or UV inkjet, or in a color filter, a black matrix or the like that is used in a liquid crystal display element or a solid-state imaging element; a color filter; and a process for producing the color filter.
2. Description of the Related Art
Oxime derivatives are widely used as medicines, agricultural chemicals, antibacterial agents, synthesis intermediates, or photosensitive compounds. Examples of the photosensitive compounds include photopolymerization initiators, photo-acid agents, and photo-base agents.
Photopolymerization technique is used as a technique for producing an adhesive, a printing plate, a semiconductor, a liquid crystal, a color filter for a solid-state imaging element, and so forth.
As photopolymerization initiators therein, various oxime derivatives are disclosed in U.S. Pat. Nos. 3,558,309 and 4,255,513, Japanese Patent Application Laid-Open (JP-A) Nos. 61-24558, 2000-80068, 2001-233842, and 2002-323762, Japanese Patent Application National Publication (Laid-Open) Nos. 2002-519732, and 2004-534797, and WO 04/050653 and WO 05/080337.
However, in photopolymerization technique, a photopolymerization initiator is desired which has higher sensitivity, thermal stability and storage stability with precipitation after application to the substrate being reduced.
Photopolymerization technique is a useful technique applicable to various uses. Examples of compositions in which photopolymerization technique can be used include: compositions for producing a colorant-containing or colorant-non-containing paint or vanish, a powdery coating material, a printing ink, an inkjet ink, a UV ink, a printing surface, an adhesive, a composition for dental surgery, a gel coat, or photoresists for electronic engineering, such as an electroplating resist, an etching resist, wet and dry thin films, and a soldering resist; compositions for producing a color filter for various display devices; compositions for forming a structure in a process for producing a plasma display panel, an electroluminescent display device, or an LCD; composite compositions; compositions for sealing a resist (including a photoresist), a color filter, a black matrix, or electrical or electronic parts; compositions for producing a magnetic recording material, fine mechanical parts, a waveguide, an optical switch, a plating mask, an etching mask, a color test agent, a glass fiber cable coat, or a screen-printing stencil; compositions for producing a three-dimensional object by stereo-lithography; an image recording material, in particular an image recording material for holographic recording; compositions for or a fine electronic circuit; compositions as discoloring materials for image recording materials in which microcapsules are used; and compositions for forming dielectric layers for successive laminations of printed circuit boards.
JP-A Nos. 2000-80068 and 2001-233842, Japanese Patent Application National Publication (Laid-Open) No. 2004-534797, and pamphlets of WO 04/050653 and WO 05/080337 disclose a photopolymerizable composition in which a specific oxime compound is used as a photopolymerization initiator.
Out of the above-mentioned applications, a color filter which is used in a liquid crystal display element (LCD) or a solid liquid crystal display element (such as a CCD, or a CMOS) is described below.
Known methods for producing a color filter which is used in a liquid crystal display element (LCD) or a solid liquid crystal display element (such as a CCD, or a CMOS) include the dye method, the printing method, the electrodepositing method, and the pigment dispersing method.
Out of these methods, the pigment dispersing method is a method of using a colored radiation-sensitive composition wherein a pigment is dispersed in any one of various photosensitive compositions to produce a color filter by photolithography, and has an advantage that the color filter has stability against light, heat and so on since the pigment is used. This method is widely used as a method suitable for producing a color filter for a large-screen and high definition color display having a high position precision since the patterning is performed by photolithography.
When a color filter is produced by the pigment dispersing method, a radiation-sensitive composition is applied onto a glass substrate with a spin coater, a roll coater or the like and then dried to form a coating layer and subsequently this coating layer is subjected to patterning-exposure to light and development, thereby forming colored pixels. This operation is repeated for the respective colors in accordance with the number of desired hues, so as to yield a color filter. As this pigment dispersing method, disclosed are examples using a negative photosensitive composition wherein an alkali-soluble resin is used together with a photopolymerizable monomer and a photopolymerization initiator (see, for example, JP-A Nos. 2-199403, 4-76062, 5-273411, 6-184482, and 7-140654).
In the meantime, in recent years, there is desire for higher definition of color filters for solid-state imaging elements. A technique has been suggested, the technique using a dye that is soluble in organic solvent, which may be referred to merely as a “dye” hereinafter, instead of the pigment (see, for example, JP-A No. 2005-99488).